Biofuels are often touted as the next big thing in airplane fuel technology, but solar power shouldn’t be discounted — as was recently proven by the team behind the Solar Impulse. The solar-powered plane just took its first test down the runway, and eventually the plane is expected to take a 20 to 25 day trip around the world.

The test saw the Solar Impulse take some slow steps down the runway using four solar-powered electric motors. The plane taxied without landing gear — just like in a normal takeoff. Now that the runway test was successful, the Solar Impulse team will taxi to takeoff speed and let the plane take off for some short “hops” in the air. Full-fledged flight tests will begin next year.

The Solar Impulse isn’t the only solar-powered plane gearing for takeoff. The Odysseus, an autonomous solar-powered surveillance craft, can fly for five years straight using only its solar panels.